1. Field of the Invention
The invention relates to a combination of screw or nut and a captive washer.
The term "screw" is to be understood herein to include any male fastening member having a screwthreaded shank for cooperation with a screwthreaded aperture or recess in a female fastening element, and the term "nut" is to be understood to include any female fastening member having a screwthreaded aperture or recess for cooperation with the screwthreaded shank of a male fastening element. In each case, a clamping surface is provided on the screw or nut for applying an axial clamping force when the screw or nut is tightened.
One application of the invention is to electrical terminals in which a wire is trapped between a body and the captive washer. The washer is provided so that as the nut or screw is tightened the wire is trapped by the axial clamping force exerted by the nut or screw but is subjected to little or no rotational force.
2. Description of the Prior Art
Known screws and nuts having captive washers tend to be relatively complicated to assemble. One example of such an assembly is formed by sliding a washer onto the shank of a screw blank and then rolling a thread on a portion of the shank remote from the screw head. The action of rolling the thread increases the diameter of the shank at the peaks of the thread, thus trapping the washer between the screw head and the threaded portion of the shank. A nut provided with a captive washer is known in which the nut has a circumferential rim over which the circumferential portion of a washer is located by a spinning operation.